Cardiac reinforcement device

ABSTRACT

The present disclosure is directed to a cardiac reinforcement device (CRD) and method for the treatment of cardiomyopathy. The CRD provides for reinforcement of the walls of the heart by constraining cardiac expansion, beyond a predetermined limit, during diastolic expansion of the heart. A CRD of the invention can be applied to the epicardium of the heart to locally constrain expansion of the cardiac wall or to circumferentially constrain the cardiac wall during cardiac expansion.

BACKGROUND OF THE INVENTION

[0001] The present invention is generally directed to a device andmethod for reinforcement of the cardiac wall. The invention isparticularly suited for the treatment of cardiac disease which result inatrial or ventricular dilation. The invention provides reinforcement ofthe cardiac wall during diastolic chamber filling to prevent or reducecardiac dilation in patients known to have experienced such dilation orwho have a predisposition for such dilation occurring in the future. Thecardiac reinforcement structure is typically applied to the epicardialsurface of the heart.

[0002] Cardiac dilation occurs with different forms of cardiac disease,including heart failure. In some cases, such as post-myocardialinfarction, the dilation may be localized to only a portion of theheart. In other cases, such as hypertrophic cardiomyopathy, there istypically increased resistance to filling of the left ventricle withconcomitant dilation of the left atria. In dilated cardiomyopathy, thedilation is typically of the left ventricle with resultant failure ofthe heart as a pump. In advanced cases, dilated cardiomyopathy involvesthe majority of the heart.

[0003] With each type of cardiac dilation, there are associated problemsranging from arrhythmias which arise due to the stretch of myocardialcells, to leakage of the cardiac valves due to enlargement of thevalvular annulus. Devices to prevent or reduce dilation and therebyreduce the consequences of dilation have not been described. Patchesmade from low porosity materials, for example Dacron™, have been used torepair cardiac ruptures and septal defects, but the use of patches tosupport the cardiac wall where no penetrating lesion is present has notbeen described.

[0004] Drugs are sometimes employed to assist in treating problemsassociated with cardiac dilation. For example, digoxin increases thecontractility of the cardiac muscle and thereby causes enhanced emptyingof the dilated cardiac chambers. On the other hand, some drugs, forexample, beta-blocking drugs, decrease the contractility of the heartand thus increase the likelihood of dilation. Other drugs includingangiotensin-converting enzyme inhibitors such as enalopril help toreduce the tendency of the heart to dilate under the increased diastolicpressure experienced when the contractility of the heart muscledecreases. Many of these drugs, however, have side effects which makethem undesirable for long-term use.

[0005] Accordingly, there is a need for a device that can reduce orprevent cardiac dilation and reduce the problems associated with suchdilation.

SUMMARY OF THE INVENTION

[0006] The present invention is directed to a device and method forreinforcement of the cardiac wall. According to the invention, a cardiacreinforcement device includes a biomedical material which can be appliedto the epicardial surface of the heart and which expands to apredetermined size that is selected to constrain cardiac expansionbeyond a predetermined limit. A biomedical material suitable for acardiac reinforcement device can be an elastic or non-elastic mesh ornon-mesh material.

[0007] In one embodiment, a cardiac reinforcement device is a biomedicalmaterial in the form of a patch. The size of the patch is selected tolocally constrain cardiac expansion.

[0008] In another embodiment, a cardiac reinforcement device is abiomedical material shaped as a jacket with a predetermined sizeselected for the jacket to surround the epicardial surface of the heartand circumferentially constrain cardiac expansion. In one embodiment, acardiac reinforcement jacket may be applied to the epicardial surfacevia a minimally invasive procedure such as thorascopy.

[0009] A cardiac reinforcement jacket can include a securing arrangementfor securing the jacket to the epicardial surface of the heart. Thecardiac reinforcement jacket can also include a mechanism forselectively adjusting the predetermined size of the jacket around theepicardial surface of the heart. The adjustment mechanism can include aslot having opposing lateral edges which when pulled together decreasethe volumetric size of the jacket. In an alternative embodiment, aselective size adjustment mechanism can include an inflatable membermounted between the jacket and the epicardial surface of the heart.Inflation of the inflatable member provides for reduction in thevolumetric size of the jacket.

[0010] A cardiac reinforcement device of the invention can be used totreat cardiomyopathy or to reduce the diastolic volume of the heart.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a frontal view of one embodiment of a cardiacreinforcement patch.

[0012]FIG. 2 is a perspective view of the cardiac reinforcement patch ofFIG. 1 in place on the epicardium of a heart.

[0013]FIG. 3 is a perspective view of one embodiment of a cardiacreinforcement jacket according to the invention.

[0014]FIG. 4 is a second embodiment of a cardiac reinforcement jacketaccording to the invention.

[0015]FIG. 5 is a perspective view of the embodiment of the cardiacreinforcement jacket shown in FIG. 3 in place around the heart.

[0016]FIG. 6 is a schematic cross sectional view of one embodiment of amechanism for selectively adjusting the predetermined size of a cardiacreinforcement jacket.

[0017]FIG. 7 is a perspective view of a placement tool which can be usedfor applying a cardiac reinforcement jacket.

[0018]FIG. 8 is a perspective view of a placement tool being employed toplace a cardiac reinforcement jacket over the heart.

DETAILED DESCRIPTION

[0019] The present invention is directed to reinforcement of the heartwall during diastolic filling of a chamber of the heart. The inventionis particularly suited for use in cardiomyopathies where abnormaldilation of one or more chambers of the heart is a component of thedisease.

[0020] As used herein, “cardiac chamber” refers to the left or rightatrium or the left or right ventricle. The term “myocardium” refers tothe cardiac muscle comprising the contractile walls of the heart. Theterm “endocardial surface” refers to the inner walls of the heart. Theterm “epicardial surface” refers to the outer walls of the heart.

[0021] The heart is enclosed within a double walled sac known as thepericardium. The inner layer of the pericardial sac is the visceralpericardium or epicardium. The outer layer of the pericardial sac is theparietal pericardium.

[0022] According to the present invention, a cardiac reinforcementdevice (CRD) limits the outward expansion of the heart wall duringdiastolic chamber filling beyond a predetermined size. The expansionconstraint applied to the heart by a CRD is predetermined by thephysician based on, for example, cardiac output performance or cardiacvolume. In contrast to known ventricular assist devices which providecardiac assistance during systole, a CRD according to the presentdisclosure provides cardiac reinforcement during diastole.

[0023] A CRD is made from a biomedical material which can be applied tothe epicardial surface of the heart. As used herein, a “biomedicalmaterial” is a material which is physiologically inert to avoidrejection or other negative inflammatory response. A CRD can be preparedfrom an elastic or substantially non-elastic biomedical material. Thebiomedical material can be inflexible, but is preferably sufficientlyflexible to move with the expansion and contraction of the heart withoutimpairing systolic function. The biomedical material should, however,constrain cardiac expansion, during diastolic filling of the heart, to apredetermined size. Examples of suitable biomedical materials includeperforate and non-perforate materials. Perforate materials include, forexample, a mesh such as a polypropylene or polyester mesh. Non-perforatematerials include, for example, silicone rubber.

[0024] A biomedical material suitable for a device of the inventiongenerally has a lower compliance than the heart wall. Even though thebiomedical material is less compliant than the heart wall, some limitedexpansion of an elastic biomedical material can occur during cardiacfilling.

[0025] In an alternative embodiment, the biomedical material can besubstantially non-elastic. According to this embodiment, the term“substantially non-elastic” refers to a material which constrainscardiac expansion during diastole at a predetermined size, but which hassubstantially no elastic properties.

[0026] Regardless if the biomedical material is elastic or non-elastic,advantageous to a CRD according to the present disclosure is cardiacreinforcement which is provided during diastole. Moreover, a CRD asdisclosed herein does not provide cardiac assistance through activepumping of the heart.

[0027] I. CRD Patch

[0028] In one embodiment, a cardiac reinforcement device (CRD) providesfor local constraint of the heart wall during cardiac expansion.According to this embodiment, a CRD is a “patch” that providesreinforcement of the heart wall at a localized area, such as a cardiacaneurysm or at an area of the myocardium which has been damaged due tomyocardial infarction. When discussing a “patch”, “predetermined size”of the patch means that the size of the patch is selected to cover anarea of the epicardial surface of the heart in need of reinforcementwithout completely surrounding the circumference of the heart.

[0029] A CRD patch can be prepared from the biomedical materialsdescribed above. In a preferred embodiment, the patch is an open meshmaterial.

[0030] A CRD patch can be applied to the epicardial surface of the heartover or under the parietal pericardium. A patch is typically applied tothe epicardial surface by suturing around the periphery of the patch.The peripheral edge of the patch can include a thickened “ring” or otherreinforcement to enhance the strength of the patch at the point ofsuture attachment to the epicardium. Generally, a patch is applied tothe epicardium through a thoracotomy or other incision providingsufficient exposure of the heart.

[0031] II. CRD Jacket

[0032] In another embodiment, a CRD is a jacket that circumferentiallysurrounds the epicardial surface of the heart. When applied to theheart, a CRD jacket can be placed over or under the parietalpericardium.

[0033] A CRD applied to the epicardium is fitted to a “predeterminedsize” for limitation of cardiac expansion. According to a jacketembodiment, “predetermined size” refers to the predetermined expansionlimit of the jacket which circumferentially constrains cardiac expansionduring diastolic filling of the heart. In practice, for example, aphysician could measure cardiac output and adjust the jacket size to anoptimal size for the desired effect. In this example, the optimal sizeis the “predetermined size”. In one embodiment, the predetermined sizecan be adjusted for size reduction as the cardiac size is reduced.

[0034] In one embodiment, the CRD jacket is a cone-shaped tube, having abase broader than the apex, which generally conforms to the externalgeometry of the heart. When applied to the epicardial surface of theheart, the base of the jacket is oriented towards the base of the heart,and the apex of the jacket is oriented towards the apex of the heart.Typically, the base of the jacket includes an opening for applying thejacket by passing the jacket over the epicardial surface of the heart.The apical end of the jacket can be a continuous surface which coversthe apex of the heart. Alternatively, the apex of the jacket can have anopening through which the apex of the heart protrudes.

[0035] A cardiac reinforcement jacket, as disclosed herein, is not aninflatable device that surrounds the heart. Rather, the device istypically a single layer of biomedical material. In one embodimentdiscussed below, an inflatable member can be included with the device,but the inflatable member serves to reduce the volume within a localizedregion of the jacket and does not follow the entire jacket to surroundthe epicardial surface of the heart.

[0036] In one embodiment, the CRD jacket can be secured to theepicardium by a securing arrangement mounted at the base of the jacket.A suitable securing arrangement includes, for example, a circumferentialattachment device, such as a cord, suture, band, adhesive or shapememory element which passes around the circumference of the base of thejacket. The ends of the attachment device can be fastened together tosecure the jacket in place. Alternatively, the base of the jacket can bereinforced for suturing the base of the jacket to the epicardium.

[0037] Various sized CRD jackets can be prepared such that differentsized jackets are used for different predetermined cardiac expansionsizes or expansion ranges. Alternatively, a CRD jacket can include amechanism for selectively adjusting the size of the jacket. A mechanismfor selectively adjusting the volumetric size of the jackettheoretically provides for a “one size fits all” device. Moreimportantly, however, an adjustable jacket provides the ability totitrate (readjust) the amount of cardiac reinforcement by gradedreduction in jacket size as therapeutic reduction of cardiac expansionoccurs.

[0038] A mechanism for selectively adjusting the size of the jacket caninclude a slot which opens at the base of the jacket and extends towardthe apex end of the CRD. If the apex end of the CRD jacket is open, theapical extent of the slot can be continuous with the apex opening. Theslot includes opposing lateral edges. By adjusting the proximity of theopposing lateral edges, the overall size of the jacket can be varied.Moving the opposing edges of the slot closer together narrows the slotand reduces the volumetric size of the jacket. The opposing edges of theslot can he fastened together at a predetermined proximity by, forexample, one or more lateral attachment devices, such as a cord, suture,band, adhesive or shape memory element attached to each lateral edge.

[0039] In another embodiment, a mechanism for selectively adjusting thesize of the jacket can be an inflatable member. According to thisembodiment, the inflatable member is mounted between the jacket and theepicardium. The volumetric size of the jacket can be reduced byinflating the inflatable member through an inflation port with, forexample, a gas or liquid. As cardiac expansion volume responds tocardiac constraint by size reduction, the predetermined size of thejacket can then be reduced by inflating the inflatable member within thejacket. Once inflated, the size of the inflatable member is preferablymaintained until therapeutic response causes a need for furtherinflation. According to the invention, the inflation of the inflatablemember provides a reduction in the predetermined size of the jacket by afixed increase in volume of the inflatable member. The inflatable memberis not rhythmically inflated and deflated to provide assistance tocardiac contraction during systole.

[0040] The biomedical material of the invention can be radioluscent orradiopaque. In one embodiment, the material of the jacket can be maderadiopaque by inclusion of radiopaque markers for identification of theoutside surface of the heart, the expansion slot or inflation port. Asused herein, radiopaque means causing the CRD to be visible on x-ray orfluoroscopic viewing. Suitable radiopaque markers include, for example,platinum wires, titanium wires and stainless steel wires.

[0041] A CRD according to the present disclosure provides a new methodfor the treatment of cardiac disease. As used herein, cardiac diseaseincludes diseases in which dilation of one of the chambers of the heartis a component of the disease. Examples include heart failure orcardiomyopathy. Heart failure can occur as a result of cardiac dilationdue to ventricular hypertrophy or secondary to, for example, valvularincompetency, valvular insufficiency or valvular stenosis.Cardiomyopathy, according to the invention, can be primary or secondaryto infection, ischemia, metabolic disease, genetic disorders, etc.

[0042] It is foreseen that constraint of cardiac expansion by a deviceof the invention can provide reduced cardiac dilation. Reduced cardiacdilation can cause reduction in the problems associated with cardiacdilation such as arrhythmias and valvular leakage. As reduction ofcardiac dilation occurs, selective reduction of the predetermined sizeof the jacket also provides continued reinforcement for the size reducedheart.

[0043] A CRD jacket can also be used to measure cardiac performance.According to this embodiment, the CRD jacket is rendered radiopaque byuse of a radiographic marker. The radiographic markers are distributedthroughout the jacket over the surface of the heart. By evaluation ofthe markers relative to one another with each heart beat, cardiacperformance may be measured. As such, evaluation of cardiac performancemay assist in adjusting the predetermined size of a CRD jacket.

[0044] A CRD as described herein can be applied to the epicardium of aheart through a thoracotomy or through a minimally invasive procedure.For a minimally invasive procedure a CRD placement tool can be used toapply the CRD over the epicardium of the heart through a thorascopicincision. According to this embodiment, a CRD placement tool includes acannula, a stiff rod or wire and a guide tube. For placement of a CRD,the wire is threaded through the guide tube which is passed around thecircumference of the base of the jacket. The CRD with wire and guidetube passed through the base opening are then passed into the cannula.The cannula is of sufficient length and diameter to enclose the CRD,wire and guide tube during passage of the placement tool through athorascopic incision. The placement tool is passed into the thoraciccavity and positioned at a point near the apex of the heart. When inposition, the wire and guide tube are pushed out of the cannula awayfrom the operator. Once outside the cannula, the wire and guide tubesufficiently expand the opening of the base of the CRD jacket to passover the epicardial surface of the heart. When the CRD jacket is inposition over the epicardial surface, the wire, guide tube and cannulacan be removed. A second incision can then be made to provide access forsuitable surgical instruments to secure or adjust the size of the CRD.

[0045] The invention will now be further described by reference to thedrawings.

[0046]FIG. 1 is a frontal view of one embodiment of a cardiacreinforcement patch 1. The CRD patch 1 shown here is a mesh biomedicalmaterial 2 having a thickened peripheral ring 3 which reinforces theperipheral edge 4 of the patch for attachment of the patch to theepicardial surface of the heart.

[0047]FIG. 2. is a perspective view of a CRD patch 10 in place on theepicardial surface of a heart 11, for example, over a cardiac aneurysm(not shown) of the heart. In one preferred embodiment, the patch 10 issized to cover the extent of the cardiac aneurysm and is placed on theepicardial surface of the heart 11. In practice, the thorax issurgically opened and the region of the heart 11 with the aneurysm (notshown) is located and exposed. The patch 10 is placed over the aneurysmand sutured in place around the periphery 12 of the patch to providesufficient constraint to prevent further dilation of the aneurysm.

[0048]FIG. 3 is a perspective view of one embodiment of a CRD jacket 15according to the invention. According to the embodiment shown, thejacket 15 is a mesh material 16, and includes a circumferentialattachment device 17 at the base end 18 of the CRD jacket. The apex end24 of the jacket 15 is closed. The jacket 15 shown also includes a slot19 having opposing lateral edges 20 and 21, and fasteners (e.g. lateralattachment device 22 and 23) for selectively adjusting the volumetricsize of the jacket 15. The CRD jacket 15 shown also includes radiopaquemarkers 25 for visualizing the surface of the heart through radiographicstudy.

[0049]FIG. 4 is an alternative embodiment of a CRD jacket 30. Similar tothe embodiment shown in FIG. 3, the embodiment of FIG. 4 includes a baseend 31 and an apex 32 end. The base end includes a circumferentialattachment device 33 for securing the CRD jacket 30 to the heart. TheCRD jacket 30 of FIG. 4 also includes a slot 34 having opposing lateraledges 35, 36. The lateral edges 35, 36 are shown pulled together at 37by a lateral attachment device 38, for example, a suture. In contrast tothe embodiment shown in FIG. 3, the embodiment shown in FIG. 4 has anopening 39 at the apex end 32 of the CRD jacket 30.

[0050]FIG. 5. is a perspective view of a CRD jacket 40 around a heart41. According to the embodiment shown, at the base 42 of the jacket 40,there is a circumferential attachment device 43 which secures the CRDjacket 40 near the base of the heart 44. A slot 45, is shown withopposing lateral edges 46, 47 fastened together by a lateral attachmentdevice 48. In the embodiment shown, the CRD jacket 40 has an opening 49at the apical end 50 of the jacket. The apex of the heart 51 protrudesthrough the opening 49 at the apical end 50 of the jacket 40.

[0051] Still referring to FIG. 5, in a preferred embodiment, if one ormore of the lateral attachment device 48 are made of an elasticmaterial, such as silicone rubber, the device can provide a way ofapplying a graded constraint around the outside of the heart 41 toreduce cardiac dilation over time. In practice, the jacket would beplaced over the heart 41 as shown, either over or under the parietalpericardium (not shown). The circumferential attachment device 43 andlateral attachment device 48 would then be tightened to cause aconstraining effect on the outside of the heart.

[0052] In a preferred embodiment, if one or more of the lateralattachment cords 48 is made of an elastic material, such as siliconerubber, surface pressure exerted on the epicardial surface of the heartvaries as a function of the amount of dilation of the heart. Thisvariable pressure has the effect of reducing the cardiac dilation to acertain point and then stopping because the surface pressure drops to anegligible amount. The amount of constraint or reduction in dilationthat is accomplished over time and the resultant cardiac performance maybe monitored radiographically using techniques known in the art, forexample fluoroscopy, by observing radiographic markers (FIG. 4, 25), ifpresent.

[0053]FIG. 6 is a schematic cross sectional view of an alternativeembodiment of an arrangement for selectively adjusting the predeterminedsize of a jacket 53. According to this embodiment, an inflatable member54 is inserted within the jacket 53 between the jacket 53 and theepicardial surface 55 of the heart 56. The inflatable member 54 includesa filling apparatus 57 for entry of a fluid (liquid or gas) to inflatethe inflatable member 54 and reduce the predetermined size of the jacket53.

[0054]FIG. 7 is a perspective view of a placement tool 60 which can beused for placement of a CRD jacket 61 around the epicardium of theheart. As shown here, the base end of the jacket 62 is held open byguide tube 63 through which is passed a wire or stiffening rod 64. Thewire 64 can be removed from the guide tube 63 by pulling on the wireextraction grip 66. The placement tool 60 includes a cannula 65 whichencloses the jacket 61, guide tube 63 and wire 64 during insertion ofthe tool into a thorascopic incision.

[0055]FIG. 8 is a perspective view of a placement tool 70 being employedto place a jacket 71 over the heart 72 on the outside of the parietalpericardium 73. The placement tool 70 is guided through a small incisionin the thorax and the jacket 71 is maneuvered into position over theheart 72. Once the jacket 71 is in proper position, the wire 74, whichis passed through the guide tube 75 around the base 76 of the jacket 71,is extracted from the guide tube 75 by pulling on the wire extractiongrip 77. The guide tube 75 is then extracted by pulling on the guidetube extraction grip 78. The cannula 79 is removed from the chest andthe circumferential attachment cord (not shown in this view), and thelateral attachment cord 80 can be fastened to secure the jacket 71.

[0056] The above specification and drawings provide a description of acardiac reinforcement device and method of using on the heart. Sincemany embodiments of the invention can be made without departing from thespirit and scope of the invention, the invention resides in the claimshereinafter appended.

What is claimed is:
 1. A cardiac reinforcement device, said devicecomprising: a biomedical material which can be applied to the epicardialsurface of the heart and which expands to a predetermined size, saidpredetermined size selected to constrain cardiac expansion beyond apredetermined limit.
 2. The cardiac reinforcement device according toclaim 1 wherein said biomedical material is an open mesh patch, saidsize selected for said patch to locally constrain cardiac expansion. 3.The cardiac reinforcement device according to claim 1 wherein saidbiomedical material is a jacket with said predetermined size selectedfor said jacket to surround the epicardial surface of the heart andcircumferentially constrain cardiac expansion.
 4. The cardiacreinforcement device according to claim 3 wherein said jacket has a baseend, said base end having an opening for applying said jacket to theepicardial surface of the heart by passing the jacket over theepicardial surface of the heart such that when applied to saidepicardial surface, said base end of said jacket is oriented toward thebase of the heart.
 5. The cardiac reinforcement device according toclaim 3 wherein said jacket has an apex end such that when said jacketis applied to said epicardial surface, said apex end is oriented towardsthe apex of the heart.
 6. The cardiac reinforcement device according toclaim 5 wherein said apex end of said jacket has an opening forprotrusion of the apex of the heart therethrough.
 7. The cardiacreinforcement device according to claim 4 wherein said base end of saidjacket further includes a securing arrangement for securing said jacketto said epicardial surface of the heart.
 8. The cardiac reinforcementdevice of claim 7 wherein said securing arrangement for securing saidjacket to said epicardial surface of the heart is a circumferentialattachment device which surrounds said opening at said base end of saidjacket.
 9. The cardiac reinforcement device according to claim 4 whereinsaid jacket includes a mechanism for selectively adjusting saidpredetermined size of said jacket surrounding the epicardial surface ofthe heart.
 10. The cardiac reinforcement device according to claim 9wherein said mechanism for selectively adjusting said predetermined sizeof said jacket is a slot, said slot having opposing lateral edges whichdecrease said predetermined size by moving said opposing lateral edgescloser together.
 11. The cardiac reinforcement device according to claim10 including a lateral attachment device for fastening together saidlateral opposing edges of said slot.
 12. The cardiac reinforcementdevice according to claim 9 wherein said mechanism for selectivelyadjusting said predetermined size of said jacket is an inflatable membermounted between said jacket and the epicardial surface.
 13. The cardiacreinforcement device according to claim 1 wherein said biomedicalmaterial is an open mesh material.
 14. The cardiac reinforcement deviceaccording to claim 1 wherein said biomedical material is a polyestermesh.
 15. The cardiac reinforcement device according to claim 1 whereinsaid biomedical material is silicon rubber.
 16. The cardiacreinforcement device according to claim 1 wherein said biomedicalmaterial includes a radiopaque marker.
 17. The cardiac reinforcementdevice according to claim 16 wherein said radiopaque marker is aplatinum wire.
 18. A method for treating cardiac disease, said methodcomprising: (a) selecting a cardiac reinforcement device, said cardiacreinforcement device comprising: (i) a biomedical material which can beapplied to the epicardial surface of the heart and which expands to apredetermined size, said predetermined size selected to constraincardiac expansion beyond a predetermined limit; (b) applying saidcardiac reinforcement device to the epicardial surface of the heart; and(c) securing said cardiac reinforcement device to said epicardialsurface of the heart.
 19. The method according to claim 18 wherein saidcardiac reinforcement device is a jacket with said predetermined sizeselected for said jacket to surround the epicardial surface of the heartand circumferentially constrain cardiac expansion.
 20. The methodaccording to claim 18 wherein said cardiac reinforcement device is apatch, said size selected for said patch to locally constrain saidcardiac expansion.
 21. The method according to claim 18 wherein saidcardiac reinforcement device is applied to the epicardial surface of theheart under the parietal layer of the pericardium.
 22. The methodaccording to claim 18 wherein said cardiac reinforcement device isapplied to the epicardial surface of the heart over the parietal layerof the pericardium.
 23. The method according to claim 19 wherein saidcardiac reinforcement device is applied to said epicardial surface viathorascopy.
 24. The method according to claim 18 wherein said cardiacdisease is heart failure.
 25. The method according to claim 18 whereinsaid cardiac disease is cardiomyopathy.
 26. The method according toclaim 19 wherein said predetermined size of said jacket is reduced ascardiac size is reduced.
 27. A method for reducing the diastolic volumeof the heart, said method comprising: (a) selecting a cardiacreinforcement device, said cardiac reinforcement device comprising: (i)a biomedical material which can be applied to the epicardial surface ofthe heart and which expands to a predetermined size, said predeterminedsize selected to constrain cardiac expansion beyond a predeterminedlimit; (b) applying said cardiac reinforcement device to the epicardialsurface of the heart; and (c) securing said cardiac reinforcement deviceto said epicardial surface of the heart.